Process for increasing the transparency of fabrics containing filament yarns



Patented Feb. 6, 1945 raocass FOR INCREASING THE TRANS- PARENCY or namesCONTAINING ma- MENT YARNS James W. Stallinn, Haddon Heights, N. 1.,asslgnor to Rohm & Haas Company, Philadelphia, Pa., a corporation ofDelaware No Drawing. Application April 24, 1941.

Serial No. 890,136

4 Claims.

This invention relates to novel fabrics which are composed at least inpart of multifilament yarns, the filaments of which are at leastpartially bonded with a transparent, film-forming. water-insolublethermoplastic resin.

It has heretofore been the practice to size filamentous yarns withspecial starches or gelatin in order to facilitate the weaving of theyarns into fabrics. After the weaving operation it has been the usualpractice to wash out the gelatin or remove the starch, even though theharshness of the sized yarn may have been lessened by mechanical actionduring weaving. If woven cloth is not desired, it becomes hard and stillwhen wet and subsequently dried. Furthermore the presence of such sizesin filamentous fabric dulls the color of dyes, increases opacity, andgenerally yields a less attractive fabric than an unsized one.

Replacement of starch or gelatin sizes with certain resinous materialshas been proposed. While certain properties of the resulting cloth maythus be rendered more permanent, the general appearance of the cloth hasnot been altered thereby or the general character of the fabric changedexcept with regard to such qualities as handle or resistance tocrushing.

It is now found that novel fabrics result from sizing multifllament yarnwith an aqueous dispersion of certain thermoplastic resins as willherein be described, incorporating the sized yarn into a fabric, wettingthe fabric with water, and drying by heating the wet fabric without sub-.iecting the resin-impregnated yarn to tension. The resulting fabricpossesses unique properties as to both handle and appearance and may bebest described as semi-transparent. It exhibits excellent drapingqualities.

In the manufacture of yarn to be impregnated there may be used any typeof filament, such as that prepared from viscose, cuprammonium cellulose.cellulose esters, glass, vinyl resins, oriented diamine-dicarboxylicacid resins, etc. Yarn com osed of multifilaments is preferably used forthe warp, but the invention is not so limited, as it may be used forfilling or for both warp and filling. When impregnated multifilamentyarn is used for warp, the filling may consist of unimpregnated yarn ofthe same type of material, or of a different type of material, includingcotton. silk, linen, wool. or the like. Similarly, these other types maycompose the warp threads while the filling threads represent theimpregnated yarns. It should be noted that the filamentous yarns may becomposed of several kinds of filaments.

Thermoplastic resins which are useful are not confined to any singlekind of resin, but may be selected from such types as the acrylic.alkacrylic, vinyl and other thermoplastic resins possess a relativelylow softening point. Effective compositions have a softening point belowabout 100 F. and yet remain amorphous solids. The suitability of theresinous composition, it has been established, depends further upon aproperty which may be described as the fiuxing point. This is thetemperature at which the thermoplastic resin will adhere to a smoothsurface. It may be determined by slowly raising the temperature of asmall light plate of metal while a piece of the resin is repeatedlyraised and lowered onto the metal plate. At the fluxing point the metalplate will firmly adhere to the piece of resin. The temperature at whichthis phenomenon is observed may be easily determined with the simplestof apparatus within :5" F. Thermoplastic resins or resinous compositionshaving fluxing points within the range of 100 F. and 250 F. have beenfound effective in producing the desired finish in textile fabrics.

Various water-insoluble thermoplastic resins may be prepared meeting thedefined conditions by controlling the degree of polymerization.Furthermore, the necessary conditions as to softening point and fiuxingpoint may be attained by the use of softeners or plasticizers.Plasticized resins are often permissible if due regard be given thepossible use to which the particular finished fabric is to be put andthe ouestion of absorption of plasticizer by fibers or their loss incleaning solutions likely to be used upon the fabric.

The water-insoluble thermoplastic resin is applied to the yarn from anaqueous emulsion or dispersion prepared with a wetting agent.emulsifying agent, and/or protective colloid. In preparing an emulsionthe resin may. if desired, be first taken up with a small amount of anorganic solvent. The dispersions may also be modified with lubricantssuch as oils or waxes. The dispersions used for the impregnation offilamentous yarn may contain up to 25% of the dis ersed material andfrom about 2% to about 5% of thermoplastic resin may be deposited on theyarn.

The preparation of fabrics accordin to this invention is illustrated bythe following examples.

Example 1 Black dyed viscose rayon yarn of 100 denier and 40 filamentswas passed through a size box containing a dispersion prepared with 8%of a mixture of parts of ethyl acrylate and 15 parts of acrylonitrilewhich had been emulsified with octadecyl dimethyl benzyl ammoniumbromide and polymerized with a peroxide catalyst. The dispersed resinhad a softening point at approximately room temperature and a fiuxingpoint of 120 F. The impregnated yarn was dried as it was passed overfive steam-heated drying cylinders at such a rate that the moisturecontent of the yarn leaving the cylinders was 5%. The dry yarn was woundon a loom beam and used for the warp of an all viscous rayon fabric inwhich the filling consisted of black-dyed, unsized 100 denier. 40filament viscose yarn. During the weaving operation there was nobreaking of filaments Consequently there was freedom from ballingup andbreakage of yarn or end breakage. In this respect the resin sizing ofthe yarn was distinctly superior to the sizing obtained with starch,gelatin or other protein. The fabric which was thus woven was paddedthrough water and dried without warp tension in a frame operating atabout 250 F.

The resulting fabric was semi-transparent, flexible, bright-colored,full and mellow. When rubbed between the fingers, there was nodistortion of the construction whereas a similar gelatin-sized fabricshowed considerable displacement of the yarns. The interstices were freeof extraneous material whereas fabrics with gelatinsized yarns showedfilling of these areas. The gelatin-sized fabric had anabrasion-resistance by the T. B. L. test of 887 cycles and theresinsized fabric of over 1300. The breaking strength of the resin-sizedwarp was 102 lbs. whereas the breaking strength of warp which had beensized with gelatin was 91 lbs.

Ewample 2 A sizing bath was prepared by mixing '7 parts of a dispersioncontaining 30% of a co-polymer made from parts of acrylonitrile and 90parts of ethyl acrylate which were mixed as monomers, emulsified withsoap, and polymerized by heating with a peroxide, 5 parts of a 50%aqueous dispersion of a co-polymer prepared from a mixture of 25 partsof ethyl acrylate and '75 parts of vinyl acetate which was emulsifiedwith octyl phenoxyethoxyethoxy sodium sulfonate and polymerized byheating, one-half part of a self-emulsifying light petroleum oil, and 60parts of water. The softening point of the resinous materials wasdetermined as about 70 F. and the fiuxing point as 110 F.

This sizing bath was applied to a web of bluedyed bright 150 denier 50filament rayon yarn (cuprammonium) on a slasher (Johnson) and dried onsteam-heated cans. The sized warp was woven into a fabric with unsizedyarn of the same sort. In the weaving of the fabric no difiiculty wasexperienced from balling-up or breakage. The woven fabric was then wetout with atomized water and dried on a stack of motor-drivensteam-heated cans without tension.

The resulting fabric was exceptionally sheer inappearance;semi-transparent, full and mellow, free from distortions, andimproved in strength.

Example 3 A sizing bath was prepared by mixing 8 parts of a 30% aqueousdispersion of a co-polymer made from 70 parts of ethyl methacrylate, 30parts of methyl acrylate and one part of octylphenoxyethoxyethoxy ethylsodium sulfonate, 2 parts of a 25% aqueous dispersion of a co-polymermade from 90 parts of ethyl acrylate and 10 parts of acrylonitrlle withone part of the above wetting agent, one-half part of the hydroxybenzyldimethylamine salt of octylphenoxyethyl sulfate, and 70 parts of water.The co-polymer of ethyl methacrylate and methyl acrylate had a softeningpoint of 95 F. and a fluxing point of 230 F., while the copolymer ofethyl acrylate and acrylonitrile had a softening point below roomtemperature and a fluxing point of F.

The sizing bath was applied to a web consisting of denier 30 filamentyarns by immersing in a size box and dressing between rollers. The webwas then passed through a hot air dryer and wound on a loom beam. Thesized yarn was woven into a lining fabric with a filling consisting ofthe same original yarn, which had been impregnated in a bath containinga dispersion of 2% of the same co-polymer of ethyl acrylate andacrylonitrile as used above and 1% of a selfemulsifying petroleum oil.The woven fabric was padded through water and dried on a frame at 260 F.and wound on a roll.

The fabric was crisp yet flexible, very smooth, sheer andsemi-transparent. The porosity of this fabric is particularly adaptedfor cool linings in summer garments.

I claim:

1. The process of preparing a novel .fabric containing multifilamentyarn which comprises sizing multifilament yarn with an aqueousdispersion of a co-polymer of an acrylic acid ester and acrylonitrilehaving a softening point below 100 F. and a fluxing point between about100 F. and about 250 F., preparing a fabric with the sized yarn, wettingthe fabric with water, and drying the wet fabric by heating above thefiuxing point of the said resin without subjecting the resinimpregnatedyarn to tension.

2. The process of preparing a novel fabric containing a regeneratedcellulose multifilament yarn which comprises sizing multifilament yarnwith an aqueous dispersion of a co-polymer of an acrylic acid ester andacrylonitrile having a softening point below 100 F. and a fiuxing pointbetween about 100 F. and about 250 F., preparing a fabric with the sizedyarn, wetting the fabric with water, and drying the wet fabric byheating above the fiuxing point of the said resin without subjecting[the resin-impregnated yarn to tension.

3. A porous, semi-transparent, flexible, mellow fabric free fromdistortion when rubbed between the fingers and having interstices freeof resins, the Warp of which consists of multifilarnent yarn ofregenerated cellulose, the filaments of which are bonded with and carryabout 2% to about 15% of a co-polymer of an acrylic acid ester andacrylonitrile having a softening point below 100 F. and a fluxing pointbetween about 100 F. and about 250 F.

4. In the process of preparing a porous, semi-" transparent, flexible,mellow fabric which has interstices free from resins and which is madewith regenerated cellulose multifilamerrt yarns sized with an aqueousdispersion of a copolymer of an acrylic acid ester and acrylonitrilehaving a softening point below 100 F. and a fiuxing point between about100 F. and about 250 F., the steps which comprise wetting with water afabric made with said sized yarns and drying the Wet fabric by heatingabove the fluxing point of said resin without subjecting theresin-impregnated yarns to tension.

JAMES W. STALLINGS.

CERTIFICATE OF CORRECT]: ON Patent No.2,568,9h8. February 6, 1-915.

JAMES W STALLINGS It is hereby certified that error appears in theprinted specification of the above numbered patent requiring correctionas follous: Page 1, first column, line 11+, for the word "desired" read--deeized--; and that the said Letters Patent should be read with thiscorrection therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 19th day of June, A. D. 19h5.

Leslie Frazer (Seal) Acting Commissioner of Patents.

